Taking to her Instagram account on Tuesday, Kourtney Kardashian shared a sweet message for Addison Easterling, who is popularly known as Addison Rae, wishing the TikTok star a happy 20th birthday. In her birthday tribute, she called her friend an "angel."

The 41-year-old Keeping Up with the Kardashians star celebrated her friend Addison Rae's big milestone on Oct. 6 by sharing a real friendship reel on the photo and video-sharing platform. In the clip, the duo coordinate in matching black outfit and ponytails as they pose together in a mirrored box truck, packed with disco balls and flashing lights.

At one point, Rae busts out a dance move after giving Kardashian a high five. She urged her followers to wish Rae, who she refers to as an "angel," a happy birthday. In the message, the Poosh founder made sure to reflect their friendship, calling the clip "a real friendship reel."

Aside from that, Kourtney took to Instagram Stories to share more photos of herself and the influencer. In one picture, they are seen donning nearly identical outfits while posing by a piano. In another picture, Kardashian and Rae are seen in matching bikinis in Lali & Layla swimwear.

Each photo was captioned with "happy," while the last photo in the series had the message "birthday!! @addisonraee." Rae opened up about her unlikely friendship with Kardashian in June, revealing that it was YouTuber David Dobrik who first made the introduction as a surprise for Kourtney's 10-years-old son Mason Disick.

Rae revealed that she met Kourtney through a friend, during an interview on Tom Ward Show. She went on to say that they surprised Mason, who liked his videos on TikTok. She and Kourtney immediately hit it off, Rae said.

Rae said she just stuck around for a while and got really close to Kourtney. They started working out together and even did a video of them doing a workout on her YouTube channel. "So that was fun," she told the host.

During an interview with PEOPLE earlier this year, Rae said Kardashian had taught her the importance of tuning out hate and deviating attention to the positive. She said Kourtney told her to appreciate and look at the bigger picture rather than getting caught up in the micro. 

She then went on to say that Kourtney also taught her to never let things get to her too much because there is so much else to feel happy about. Addison Rae turned 20 on Oct. 6.